Flight 612 was served by a RussianTupolev Tu-154M airliner (registration: RA-85185), operated by Pulkovo Aviation Enterprise. The aircraft did not refuel in Anapa and departed on time. "The Pulkovo Airlines flight departed Anapa as scheduled. All necessary maintenance was performed as required before departure," said Oleg Tolstyh, General Director of Anapa's Vityazevo Airport. Airline records show that the aircraft, manufactured in 1992, had been in service for approximately 24,215 flight hours. It was part of the Sichuan Airlines fleet until Pulkovo Aviation Enterprise acquired it in 2001. The pilot of the aircraft had over 12,000 hours of flying experience, 6,000 of which were as a pilot of a Tu-154.

"On Tuesday, at 15:37 (Moscow Time), a Tu-154 airliner of the St. Petersburg-based Pulkovo Airlines sent an SOS signal and disappeared from radar contact at 15:39 (Moscow Time)," Channel One reported. "Preliminary data suggests that the plane crashed 45 kilometers (28 mi) north of Donetsk."[2] Later it was determined that the plane crashed near the village of Sukha Balka.[citation needed]

"At an altitude of 11 500 metres (37,000 feet), the aircraft sent three SOS signals, dropped sharply in altitude and sent another SOS at 3000 metres (9,000 feet)," said Anatoli Samoshin, vice Flight Operations Director at Pulkovo Aviation Enterprise. There were no other communications.

Approximately 260 rescue personnel arrived at the scene which was blocked off by the authorities. The field of debris and bodies was about 400 metres (1,300 feet) in length. On Wednesday, Ukrainian emergency service personnel concluded their search for bodies, confirming that 170 people perished in the accident.[3] Due to the extensive crash forces and post-accident fires, rescuers believed that it would be very difficult to identify the majority of the victims on site. The aircraft belly flopped in a swampy area, breaking up on impact. The search for black boxes, which was interrupted for the night, concluded in the morning when both recorders were found. The flight recorders were later transported to Moscow for analysis.

The crash was witnessed by a local farmer and a young couple seeking shelter from the rain. They told reporters that they saw the aircraft falling out of the sky and that it burst into flames upon hitting the ground. They could see people in a number of seats that were thrown out of the aircraft on impact, but none showed any signs of life.

Early reports suggest that Flight 612 may have been caught in a thunderstorm; immediately prior to the crash, the pilots notified air traffic control that they were experiencing severe turbulence. According to the residents of a nearby town, the weather at the time of the crash was violent enough to cause power outages and cell phone disruptions on the ground. Authorities on the scene have speculated that the aircraft was struck by lightning which may have initiated an onboard fire. However, another theory has since been proposed. Based on various information, including the partially decrypted from a recovered flight recorder, crash investigators believe that the aircraft climbed to an altitude higher than the maximum for which it was designed, causing the aircraft to enter into a flat spin from which it never recovered.[citation needed]

Interstate Aviation Committee after initial decoding of flight recorders data issued the following flight safety recommendations: avoid entering thunderstorms, follow all maximum height limitations based on aircraft load and outside air temperature, and to improve pilot training when working in these situations. According to Annex 13 "Aircraft Accident and Incident Investigation" of Chicago Convention IAC does not issue information to public about people or organisations responsible for a crash—the only goal of an IAC investigation is to improve flight safety. Determining the guilty parties can be done only during trial.

The MAK final report concluded:

The cause of the crash of the Tu-154M RA-85 185 airlines "Pulkovo" was the aircraft entering in manual flight mode, supercritical angles of attack and stall mode with the subsequent transition to a flat spin and collision with the ground with a large vertical velocity. In the absence in the Flight Manual (RLE) and crew training programs of recommendations on peculiarities of piloting in the longitudinal channel in manual mode and using the trim mechanism, and inability to work on the skills of piloting the aircraft in hand mode at high altitudes and angles of attack due to the lack of appropriate simulators, the crew while avoiding area of thunderstorms and turbulence allowed the aircraft to enter pitch oscillations exceeding the operational range of angles of attack. Lack of control over flight speed and not following the instructions of RLE to prevent the aircraft entering stall mode and poor crew coordination allowed the situation to escalate into a catastrophic one.[1]

There were 160 passengers and 10 crew members aboard the aircraft. Among the passengers, 115 were adults and 45 were children under 12 years old. Among the adults, 8 were over 60 (including a 92-year-old woman who flew with one of her grandsons and his wife and two of her great-grandchildren). Earlier reports by the media and by the airline indicated that 159 passengers were on the flight, 39 children under 12 and six infants under 2 years of age. Some other sources reported that plane was carrying 171 people.[4] Authorities could not explain the discrepancy with numbers and ask to wait for expert analysis to be completed.[5]

Ukraine held a national day of mourning for the people killed in the plane crash on Wednesday August 23 and shifted celebration of their 15th Independence Day from August 24 to August 26.[6] Russia held a national day of mourning on Thursday August 24, 2006.[7]

Investigators combing the site found 171 bodies and one fragment but authorities were unable to explain the discrepancy with the flight list—which registered 160 passengers and 10 crew—saying expert analysis would be required.[citation needed]